Abstract
Laminated beams are engineering products consisting of two or more layers of lamina wood that are reexposed in the direction of longitudinal fibers. Natural resources in the form of wood are the potential to be used as building materials. Wood has some advantages, among others: mild, resistant to earthquakes, easy in the implementation. The use of wood as a structural material is for the purposes of building materials or other buildings, the creation of horses, the frame of the bridge to the aircraft hangar. For various structural purposes, it takes a large enough wood dimension with a long span. One of the ways that can be done to get wood with the desired dimensions is with laminated techniques. In the manufacture of laminated beams, the preparation of each layer can be arranged so that it can improve the properties of the wood power used. The purpose of this research is to know the influence of wood variation (Sengon wood) is the most optimal for the voltage of laminated beams.
This research is done by making test objects with a balanced arrangement where the top and bottom layers of laminated beams have the same dimensions, namely using Meranti wood and wood stuffing using Sengon wood. The test material is made with a variation of the addition of Sengon wood as high as 20%, 27%, 33%, 38, and 42% of the beam height with a span of 90 cm, each variation of 3 test objects. Flexible testing carried out with the centralized load of beam spans supported by joints and roller focus in addition to strong bending data, Lendutan test objects are also measured by placing dial gauge at each of the 1/4, 1/2, and 3/4 landmarks.
The results show that the thicker the Sengon wood is the higher the strength of the laminated beam that is depicted with the burden received by the beam is increasing. At the addition of the field of Sengon Wood as high as 20% and 27% of the total height of the laminated beam, the strength of bending that occurs exceeds the bending power of the constituent wood intact, both the whole strength Meranti and Sengon. The addition of the wood Sengon field as high as 33% to 42% of the total height of laminate beams occurs a decrease in bending strength. The optimum bending strength is in preparation with the addition of Sengon wood less than 27% of the total height of laminated beams. Extension that occurs in each beam is still in the condition of the elastic chart indicates a linear condition, and when the beam is not elastic added load and extension is not balanced anymore, the load is no longer increase, but the extension is still increasing until the beam experienced a total collapse, the thicker the Sengon wood, the extension that occurs increasingly smaller, and the greater stiffness, and vice versa if the greater the rigidity of the burden that can be received is greater. All variations of the early damage laminate beam start from the destruction of Meranti wood on the outer layer side, with the addition of the stuffing Sengon 20%, 27%, 33% and 38% of the total height of the laminated beams have collapsed, while in the beam with the addition of Sengon 42% field of the total height of the laminated beams have collapsed sliding.
Keywords: Laminated beam, balanced arrangement, lecture voltage